Like the last person mentioned, it's possible that he doesn't know exactly how to reconnect because of however the breakup went. Or. He could be waiting for you to make the first move.
In any case, breaking up to leave for college isn't really uncommon. And for the most part it's not exactly something personal meant to be done AGAINST you. I had to end a relationship for the same reason. While I'm not an example for everyone, here's what went through my mind: I'm going away to college. Long distance relationships arent my thing. I need to contact, the moments spent together, and yes, the sex (although, if a bond is strong enough, and the will of each person is as well, it's also common that people save themselves). Then I think to myself that if I were to meet someone while in college, I wouldn't want to be held back from exploring that interest. Nor would I want to hold back the girl I'm with for selfish reasons. I do believe that if you let something go, and it comes back to you, then it can be yours. Of course, that's not always the case.
Coming back home was interesting. Of course, there was that girl who I once had a passionate connection with. But things were different. We were older, experienced different things. In the long run, we became friends again. Of course there were flashes of the old days. And we did act upon our instincts at times. But in the end, we agreed to remain friends. It wasn't the end of the world for either of us.
I can't speak for his intentions, and thats something that you'd have to find out for yourself, if you're willing. Unfortunately, sometimes people come back into your life because its more comfortable than testing the waters. I would say to continue doing what you're doing. Don't engage necessarily unless you feel that compelled to do so. And things will go as they should. If he wants you back bad enough, he'll make the first move. If you WANT him back, truly, and not for the purpose of just familiarity, then you make the first move. You have to think about what's best for yourself in the long run.
Feel free to message my inbox if you'd like. I'll be happy to let you in further on my experiences with this. Take care.